Calling device



A. T. PALMER.

CALLING DEVICE.

APPLICATION FILED mmzo. 1919.

1 ,388,368 Patented Aug. 23, 1921.

2 SHEETS-SHEET l- O H i A57 i i a P 7 33 40 .38 Z5 3 I (J) 167 //vv:/v TOR 8 A. T. PALMER.

CALLING DEVICE.

APPLICATION FILED MAR. 20, 1919.

Patented Aug. 23, 1921.

2 SHE'ETSSHEET 2.

- -Of Fig. 1,

2-2 of Fig. 1.

UNITED STATES PATENT OFFICE.

ALFRED '1. OF MEDFORD, MASSACHUSETTS.

CALLING- DEVICE.

Specification of Letters Patent.

Patented Aug. 23, 1921.

Application filed March 20, 1919. Serial 110.288,!354.

tems, or the like, and has for its objects the housing of the calling mechanism within a hollow base such as may beemployed in a usual form of telephone desk-set, and the further simplification of the mechanism itself, said mechanism being preferably mounted, as a unit, upon the base-plate which serves as a floor to such desk-set. The invention further consists in novel and practically noiseless means for setting up the calling impulses, and in the means employed for introducing a' near-central pedestal within'the path of motion of the manual means which effect the impulses, without thereby materially redu impulses that may be sent.

It will be noted that the embodiment of applicants invention illustrated in the drawings is designedfor use with a non-coordinating type of selector switch,-that is, a

switch requiring but one setting of the calling lever; consequently, a variable stop is employed, i. e.,one various positions to change the amplitude of motion permitted to said lever, in contradistinction from that style of calling lever used with a coordinating type of switch, wherein the stop is fixed in one position.

In the drawings that accompany andform I part of this specification, I have illustrated my'invention as applied to and made part of a telephone desk-set which is adapted to perform the other usual functions undisturbed; and the figures are described as follows: I

Figure 1 is a general elevation of a telephone desk-set equipped with my invention, parts being broken away for clearnessof comprehension. I

Fig. 2 is a partial plan section on line Fig. 3 is an enlarged general 'plan view, in section on line 3-3 0 Fig. 1. j

Fig. 4 is an under plan section on line 2-2,

cing the number of.

q 'to carry the bar and that may be set in Fig. 5 is an enlarged detail, in section on line 5-5 of Fig. 2.

Fig. 6 is an enlarged fragment of Fig. 1.

l The base B, pedestal P, transmitter T,

receiver R, receiver-hook H and receiverswitch S are shown in substantially the ordinary relative positions, excepting that the pedestal P is slightly removed from its usual central position onbase B so as to permit proper action of the calling-lever 1 and the stoplever 2. This removal is slight in amount and leaves pedestal P in the paths of motion of levers '1 and 2; and-it is quite within the scope of my invention to employ said pedestal to limit the extreme movements of said levers, if it is desired so to do.

Referring to the base B, Figs. 1, 3 and 4, I employ a base-plate 3, preferably covered with a felt layer 4, a top-plate 5,'and a canopy 6, the last being preferably of pressed metal and having a near-central opening that is provided, around thegreater portion of its periphery, each adapted to snugly house, in turn, the arrow 8, said arrow beingmounted on stoplever 2 and adapted to hold said lever against rotation on its axis 9 while arrow 8 is in any of thenotches 7 Stop-lever 2 is shown as a flat andsomewhatelastic bar and is provided with a handle.10. To change arrow 8 from one notch to another, a slight downward pressure on handle 10 is necessary the arrow away from the under surface of the canopy adjacent to the notched opening, after which handle 10,

still held depressed, may be swung to any desired position and released. After'setting stop-lever 2, with its arrow 8 in the desired notch 7, the calling-lever 1 is operated by grasping its handle 11. and turning the lever until the down-turned lug- 12 v(Fig. 6)- brings up against the bar of stop-lever 2, and then releasing handle 11, whereupon a coiled spring 13 operates to return calling-lever 1 to its initial position.

and 5 as being joined I show plates 3 of a series of posts 14 through the agency with a series of notches 7,

and screws 15, so that the calling mechanism may be mounted therebetween as a unit. Canopy 6 screws 16 to corresponding ears 17 out displacing the calling mechanism.

Pedestal Pis shown hollow and mounted on a hollow, upwardly-projecting boss 18, which forms part of top-plate 5. A screw may be secured by a series of I on base-1 plate 3, so it may readily be removed withtial features of this mechanism are the makmg and breaking of a circuit at some measured speed as, say, ten or twelve per second,

and the pre-determination-of the number of times the circuit is to be-closed; it being understood that, when the mechanism is in normal position, this circuit is open.

In the form illustrated, this mechanism comprises a'star-wheel 21 (Fig. 4) and a pair of contact-springs 22 and 23 mounted as a switch in some usual manner, and insulated from each other in said mounting. The spring 22 is backed with a blade 24, the latter being of insulating material, and they may be firmly united throughout their length 01' they may be in separate blades, as desired. Spring 22 is preferably mounted radially with respect to star-wheel 21 and the tips of leaves 22 and 24 project slightly within the periphery of' the teeth 25 of wheel 21. The other spring, 23, is sufficiently elasticto engage the tips of teeth 25 with sufficient pressure to insure good electrical contact. The teeth 25 are formed on the metallic periphery of star wheel 21 and are preferably insulated from the shaft 26 by means of an insulating bushing 27. When star-wheel 21 is rotated in the direction of the arrow, the metal blade 22 will intermittently contact with the various teeth distant point X, the wires Y 25, each tooth serving to close the circuit and send one impulse to the switch-board. When wheel21 is rotated in the opposite direction,

the insulated blade 24 will contact the teeth 25 and no impulse is sent.

The connectors are, in general, omitted in the drawings as they do not form part of a simple diagram of a possible circuit'to a and W being connected to the terminals of springs 22 and 23, respectively. l

A source of energy is represented by the battery Z. j This circuit, normally open at star-wheel 21, may be alternately closed and opened by the rotation of saidwheel 21 in, the direction of the arrow, as above noted.

I prefer to make the mounting of springs 22 and 23 adjustable, in order to take up purpose, I mount the switch on a-block 28, said block being held by screws 29 through slots 30 in said block. A lug 31, threaded, may receive an adjusting screw 32, in a' manner in Fig. 4.

Star-wheel 21"is loosely mounted on shaft 26 bat isrigidly, connected toapinion 33 a series of spring-pressed that is clearly shown thereby rotating gear 34 and star-wheel 21 but causing no closure of the circuit W, Y. When lever'l is released, spring 13- will automatically' return it-to normal position (Fig. 3)

and again rotate gear 34 and starwheel 21,

but in the opposite direction. This return rotation, in the direction of the arrow in Fig. 4, will cause a seriesof makes and breaks in circuit W, Y, agreeing in number to the notch 7 employed. Star-wheel 21'is shown with eight teeth but I do .not limit myself to any particular number for, as will be later noted, the speed of return of lever 1 may be regulated to insure the proper number of impulses per second irrespective of the number of teeth 25. It is preferable, however, to so proportion the spacing of notches 7 that star-wheel 21 will give a corresponding number of impulses, but this is a mechanical detail.

In practice, it is desirable that lever 1 may be set at any speed natural to the fingers of the operator; lateithe speed of thereturn so as to insure proper intervals between the impulses of star-wheel 21, in order that each impulse may have time to deliver its effect before the next overtakes it. For this reason, I introduce a drag upon the return of lever 1 in the form of a governor 35 (Fig. 2), of any usual construction, said governor being fast with a pinion 36 on an auxiliary shaft 37,

In mesh with pinion 36 is agear 38, loose on shaft 26, but so positioned as to be rotated by pinion 33 on the return only of lever 1. To insure the proper action of gear 38, I form a ratchet 39 fast upon pinion 33, and pawls 40 pivotally mounted on gear 38" so that, when lever 1 is 'being's'et, ratchet 39 slips by the pawls 40,

but, upon the return of lever 1, ratchet 39 engages pawls 40 and thereby actuates governor 35 to regulate the return speed. I do not limit myself to the form of drag illustrated. 7 V

' Referring to the unit. construction of'the calling mechanism, I have shown, in Fig. 4, several features which, while not essential to the spirit of this invention, are, nevertheless, capable of use in the forming of apractical calling device for telephone sub-station equipment. Thus, 41 represents what may be termed an off-normal switch adapted for operation by an insulated boss but it is preferable to regu- 42 mounted on a spoke 43 of gear 34. Also, 44 represents a switch usable in connection with a ringing button 45. Again, 46, 46 are two insulated segments adapted for the mounting of a series of terminals 47 etc.

All of the above, as well as block 28, are preferably mounted on a spider 49, which may be secured to top-plate 5 by screws 50. 50.

I do not limit myself to the form of calling mechanism illustrated, except within the scope of the appended claims.

What I claim is:

1. A telephone base; calling mechanism within said base; a shaft operatively connected with said mechanism and havingone end projecting through said base; a lever fast on the projecting end of said shaft; a variable stop adapted to limit the movement of said lever in one direction; and a telephone pedestal mounted on said base and so positioned as to limit the movement of said lever in the other direction.

2. A telephone base; calling mechanism within said base; a shaft operatively connected with said mechanism; a lever fast on said shaft; a stop adapted to be set in a plurality of positions, all within the path of motion of said lever; and a telephone pedestal mounted on said base and positioned within the path of motion of said lever.

3. A telephone base; calling mechanism within said base; a shaft connected with said mechanism; a calling lever fast on said shaft; a stop lever loosely mounted on said shaft; means for setting said stop lever in various positions, all within the path of motion of said calling lever; and a telephone pedestal mounted on said base and within the path of motion of said calling lever.

4. In a calling device, a hollow base for a telephone desk-set; impulse-sending mechanism mounted within said base; a rotatable lever positioned exteriorly with respect to said base; a variable stop for limiting the rotation of said lever in one direction; automatic means for rotating said lever in the opposite direction; a pedestal mounted on said base and positioned to limit said rotation in the opposite direction; and means whereby said automatic means shall cause the operation of said mechanism.

5. In a'calling device, a wheel; a metallictoothed periphery on said wheel; a contactspring radially mounted with respect to said wheel and having its free end positioned within the periphery of said teeth; a second contact-spring insulated from the first contact-spring and so positioned as to be constantly in metallic connection with said toothed periphery; and means for rotating said wheel.

6. In a calling device, pinion in mesh with said gear; a toothed metallic wheel adapted for rotation by said pinion; a contact-spring radially positioned with respect to said wheel and having its free end projecting within the outer periphery of said wheel; and manual means for rotating said gear. I

7. In a calling device, a toothed, metallic wheel; a contact-spring radially mounted with respect to said wheel and having its free end projecting within the outer periphery of said wheel; insulating means mounted on one side of said free end; and means for rotating said wheel in both directions.

8. In a calling device, a toothed, metallic wheel; a contact-spring radially and adjustably mounted with respect to said wheel; insulating means mounted on one side of the free end of said spring; and means for rotating said wheel in both directions.

9. n a calling device, a rotatable wheel with a metallic, toothed periphery; a metallic elastic blade positioned radially with respect to said wheel and having its free end positioned to contact with said teeth when said wheel is rotating in one direction; and means for rotating said wheel in both directions.

10. In a calling device, a rotatable wheel with a metallic toothed periphery; a metallic elastic blade positioned radially with respect to said wheel and having its free end positioned to contact with said teeth when said wheel is rotating in one direction; means for rotating said wheel in both directions; and means for automatically retarding said rotation in said one direction.

11. In a calling device, a shaft; a gear mounted on said shaft; manual means for rotating said gear in one direction; a movable stop for limiting said rotation; automatic means for rotating said gear in the opposite direction; a fixed stop for limiting said latter rotation; a rotatable impulsewheel; means for causing said gear to rotate said wheel in both directions; and automatic means for retarding said latter rotation.

ALFRED T. PALMER.

a rotatable gear; a 

